1. Field of the Invention
The present invention relates, generally, to hydraulic couplings and, more specifically, to a hydraulic coupling having an improved hydraulic porting path design.
2. Description of the Related Art
Hydraulic couplings are well known devices used in vehicle drivetrains. Typically, hydraulic couplings are operatively supported within a housing and are in fluid communication with a source of hydraulic fluid. These devices operate to couple a pair of rotating members, such as drive shafts or axle half shafts about a rotational axis. Thus, hydraulic couplings have been employed as a part of transfer cases that operatively couple the front and rear axles of a vehicle, in limited slip and locking differentials used to couple axle half shafts, as well as other applications commonly known in the art.
While hydraulic couplings known in the related art have generally worked for their intended purposes, certain deficiencies still remain. For example, hydraulic couplings typically use a source of pressurized fluid to actuate a coupling member to couple the associated rotating shafts together. However, when coupling of the shafts is not desired, there still may remain a residual back pressure in the system which causes an increase in drag through the coupling and can increase the noise, vibration and harshness (NVH) when the hydraulic coupling is operating in an open condition. In addition, there remains a need in the art to reduce the packaging space required for hydraulic couplings and to simplify the overall design of devices used for these applications.